Crystal structure of -aconitate decarboxylase reveals the impact of naturally occurring human mutations on itaconate synthesis.

-Aconitate decarboxylase (CAD, also known as ACOD1 or Irg1) converts -aconitate to itaconate and plays central roles in linking innate immunity with metabolism and in the biotechnological production of itaconic acid by We have elucidated the crystal structures of human and murine CADs and compared their enzymological properties to CAD from Recombinant CAD is fully active in vitro without a cofactor. Murine CAD has the highest catalytic activity, whereas CAD is best adapted to a more acidic pH. CAD is not homologous to any known decarboxylase and appears to have evolved from prokaryotic enzymes that bind negatively charged substrates.